// Tell the library which of your `NSManagedObject` subclasses that conform to `EntryPersistable` should be used when mapping API resonses to CoreData entities.
let entryTypes = [Author.self, Category.self, Post.self]

// Initialize the data store and it's schema.
let store = CoreDataStore(context: self.managedObjectContext)
let persistenceModel = PersistenceModel(spaceType: SyncInfo.self, assetType: Asset.self, entryTypes: entryTypes)

// Initialize the Contentful.Client with a persistenceIntegration which will receive messages about changes when calling `sync methods`
self.client = Client(spaceId: "<YOUR_SPACE_ID>", accessToken: "<YOUR_ACCESS_TOKEN>")

// Create the manager.
self.syncManager = SynchronizationManager(client: self.client,
                                          localizationScheme: LocalizationScheme.all, // Save data for all locales your space supports.
                                          persistenceStore: self.store, 
                                          persistenceModel: persistenceModel)

// Sync with the API. 
self.syncManager.sync { _ in
  do {
    // Fetch all `Posts` from CoreData
    let post: Post? = try self.store.fetchAll(type: Post.self, predicate: NSPredicate(value: true))
  } catch {
    // Handle error thrown by CoreData fetches.
  }
}

import Foundation
import CoreData
import ContentfulPersistence
import Contentful

// The following @objc attribute is only necessary if your xcdatamodel Default configuration doesn't have your module
// name prepended to the Swift class. To enable removing the @objc attribute, change the Class for your entity to `ModuleName.Post`
@objc(Post) 
class Post: NSManagedObject, EntryPersistable {
      
    // The identifier of the corresponding Content Type in Contentful.
    static let contentTypeId = "post"

    // Properties of the `sys` object of Contentful resources.
    @NSManaged var id: String
    @NSManaged var localeCode: String?
    @NSManaged var createdAt: Date? 
    @NSManaged var updatedAt: Date?

    // Custom fields on the content type.
    @NSManaged var body: String?
    @NSManaged var comments: NSNumber?
    // NOTE: Unlike date fields in sys properties, this library can't store `Date` for custom fields.
    // Use `String` and map to date after fetching from CoreData
    @NSManaged var customDateField: String? 
    @NSManaged var date: Date?
    @NSManaged var slug: String?
    @NSManaged var tags: Data?
    @NSManaged var title: String?
    @NSManaged var authors: NSOrderedSet?
    @NSManaged var category: NSOrderedSet?
    @NSManaged var theFeaturedImage: Asset?

    // Define the mapping from the fields on your Contentful.Entry to your model class. 
    // In the below example, only the `title`, `date` and `author` fields and `featuredImage` link will be populated.
    static func fieldMapping() -> [FieldName: String] {
        return [
            "title": "title",
            "featuredImage": "theFeaturedImage",
            "author": "authors"
            "date": "date"
        ]    
    }
}

extension Post {

    var theTags: [String]? {
        guard let tagsData = self.tags else { return nil }
        return NSKeyedUnarchiver.unarchiveObject(with: tagsData) as? [String]
    }
}